int QSget_named_pi (QSprob p, const char *rowname, double *val)

/* p is an initialized QSprob, a handle to an existing LP problem  */
/* Get the value of the dual variable for constraint r2.           */

int rval;
double val;

rval = QSget_named_pi (p, "r2", &val);
if (rval) {
    fprintf (stderr, 
             "Could not get the dual value, error code %d\n", rval);
} else {
    printf ("Dual value = %.6f\n", val);
}